Regrettably, not only is the information presented here extremely cursory, but worse, most dates are speculative. If you are able to correct or supplement any of the detail below, please 'Contact me'… together we may be able to piece-together a more creditable history.
In Chris Cartwright's 'Merit Marks Board' photo the school motto can be seen as "Nunquam Otio Torpebat" - "Never known to be idle".
School houses in the '50s were named after saints: Bede, Damien, and Francis. Were the same house names used during Miss Hinchy's reign?
1927-1930 - A "Day and Boarding School for Girls" was founded at 23, Marsh Lane (- Kelly's Directory of Middlesex 1926 and 1933, and Brenda Metge)
1936 - Boys were admitted to the preparatory school (- Michael Pierce). There was also a kindergarten. The school was renamed St Brendan's School. A grass tennis court consumed part of the garden.
1939 - Mr A M Hinchy, the joint director of activities (with Miss V M Hinchy), departed the school (p530, Kelly's Directory 1939) - presumably taken by hostilities.
1950 - Headmistress Hinchy was supplanted by the 'Beauvoisin' husband-and-wife team. The 'Beau's were accompanied by eldest son Christopher, son Tony and daughter Susie - Susan Johns.
1954 - A portion of back garden was ashphalted for a playground/ tennis court.
1972 - Large properties in Marsh Lane were ripe for re-development (into flats). The school was sold and the site re-developed.